Solid pharmaceutical preparations are sometimes film coated to lessen side effects, decrease the number of doses, mask the bitterness of a drug, and the like. Film coating can be performed on tablets and granules, but a uniform coating film must be formed to precisely regulate the release rate of the drug. For granules, the use of spherical core particles of uniform particle size makes uniform coating possible. Since tablets are the drug form most preferred by patients among the solid pharmaceutical preparations, it is preferable to combine other excipients with such film-coated granules and form tablets. Orally disintegrating tablets that can be taken even without water are also more preferred among tablets for raising the patient's compliance.
However, the disintegration time and palatability of conventional orally disintegrating tablets within the oral cavity were sometimes not necessarily satisfactory. There is also the technical problem of assuring tablet hardness so that cracking and wear do not occur during manufacture and distribution. Therefore, the development of more perfect orally disintegrating tablets having suitable hardness and rapid disintegrability and techniques for their manufacture is anticipated.
Patent Reference 1 describes drug-containing granules, the surface of which is coated by a specific film-coating layer.
Patent Reference 2 discloses a rapid-disintegrating compression-molded article (orally disintegrating tablet) containing excipient and the sugar alcohol erythritol.
Patent Reference 3 discloses an orally disintegrating tablet containing three components: the sugar alcohol erythritol, crystalline cellulose, and crospovidone, which is a disintegrant.
Patent Reference 4 discloses an orally disintegrating tablet containing a main drug, sugar alcohol, celluloses, disintegrant, and sweetener.